Snow disks of the type wherein the annular rim is secured to the socket portion by leather straps have been known for a long time. Recently this type of snow disks has been manufactured also of plastic. This type of snow disk is superior to all known disks where it is desirable to provide a large supporting surface in order to prevent the ski stick from plunging deep into a soft snow bank. Since it is readily pivotable relative to the ski stick, the disk can be given large surface area without its resisting the pivoting movement of the ski stick or causing the ski stick prong to bounce off the surface. With leather straps as support straps, there were no major drawbacks in the function of a ski stick. However, mostly for economic reasons, the tendency has been to switch to plastic materials also in this type of snow disks.
As a support rib material, however, plastic is stiffer than leather which is why the snow disk is no longer as readily pivotable relative to the ski stick. For example, in up-hill skiing, a result of this is that the front rim of a snow disk of large surface area meets the base preventing gripping of the prong, with the ski stick thus "slipping off." The front rim of the disk is also likely to make the ski stick prong bounce off the base toward the end of the thrust with the stick in inclined position, whereby the thrust cannot be completed with full force. This, of course, gives rise to the idea of positioning the awkward front rim of the disk near the ski stick, as disclosed in applicant's U.S. Pat. No. 3,963,254. It should be noted, however, that the solution known from the patent deals with a stiff plastic snow disk which is why shifting of the disk front rim is possible. This is not the case with the present snow disk which is readily pivotably attached to the ski stick by means of flexible radial support ribs. If such a disk is placed asymmetrically relative to the stick, a result will be uneven load distribution on the disk surface and a readily pivotable snow disk will turn to the position nearly parallel to the stick, whereby the disk will dive with the front rim leading into a snow bank. In such a situation, a large supporting surface is of no use. Thus, there has been no way of utilizing in readily pivotable snow disks those advantages of an asymmetrical disk that are achieved in stiff plastic snow disks.